TR6 Cooling system filling

[steveg]

Are there any special techniques for filling the cooling system? The radiator cap looks to be lower than the thermostat housing.

The manual is unhelpful and AFAIK doesn't list the capacity. Moss says 13.2 pints (assume these are US not imperial).

 

[charlie74]

I think it is worth the effort to get the front of the car on stands or ramps, remove the thermostat and then fill with the heater valve open as well.

 

[Tybalt]

What charlie74 said, I use that method and it works reasonably well. You don't even need to bring the front end up all that high, just high enough that the radiator cap/filler is the highest point in the system. Then I cap up the radiator and install the thermostat and put some coolant in reservoir. Fire it up and let it come to temp and top up the reservoir if it pulls any coolant out of it when it gets up to temp.

As for capacity, it is listed on page 36 in the Bentley manual with an antifreeze mix table on page 58. Capacity is 11 Imperial pints, 13.2 wimpy undersized US pints or 6.4 L for the metricated folks. Since none of those correspond to exact conversions, my put is that those published capacities are all close enough to work but are all off by a little bit. In other words, they're close enough for an engineer but would drive a scientist mad.

 

[poolboy]

I've refilled mine a few times from the T-stat housing.

 

[steveg]

Tybalt,
Thank you for the page refs and clarification. Newbie oversight on my part.

 

[Andy Blackley]

I found the Lisle Spill Free Funnel to be very handy for filling the cooling system without the need for ramps etc: https://www.lislecorp.com/specialty-tools/spill-free-funnel-606

it comes with an adapter cap that fits on our radiators, and you fill the funnel well above the thermostat level, open the heater valve and run the car at idle until the thermostat opens and all of the air is expelled from the system. Turn the engine off and after it has cooled then remove the funnel with the yellow stopper and you are done. Pour the excess back into the antifreeze jug.




The downside is that it is a bit pricey for a funnel, but it does the job, and quickly too. There are several You-tube videos that show how you can make your own.

 

[DarvinR]

What charlie74 said, I use that method and it works reasonably well. You don't even need to bring the front end up all that high, just high enough that the radiator cap/filler is the highest point in the system. Then I cap up the radiator and install the thermostat and put some coolant in reservoir. Fire it up and let it come to temp and top up the reservoir if it pulls any coolant out of it when it gets up to temp.

As for capacity, it is listed on page 36 in the Bentley manual with an antifreeze mix table on page 58. Capacity is 11 Imperial pints, 13.2 wimpy undersized US pints or 6.4 L for the metricated folks. Since none of those correspond to exact conversions, my put is that those published capacities are all close enough to work but are all off by a little bit. In other words, they're close enough for an engineer but would drive a scientist mad.

Great tips here. We'll be working on the TR6 after I finished installing the shocks and atv accessories on the TRX project. Got to find a good elevated space here to lift the car. Going to check the Bentley manual if that can help us a lot for the TR6 project.

 

[steveg]

Thanks to Andy above for showing the coolant funnel with stopper - I hadn't been aware of those. Bought one on Amazon (different brand) and used it. Worked like a charm! Just had the radiator serviced for a leak, also installing a 1/8" NPT bung in the top tank for the electric fan thermo switch and a 1/4" NPT bung in the bottom for a drain tap. I had run Thermocure for a couple of weeks to clear out the rust and am going to run this Tefba filter for a while to capture any loose rust bits.

When I removed the funnel, given the radiator cap is lower than the thermostat, not sure why no coolant overflowed the radiator.

Nice being able to fill the system without undoing the thermostat cover.